准确估计遗传参数,揭示更多的产奶量和品质遗传变异,有利于奶牛的遗传改良。在这项研究中,我们估计了奶牛的五个与牛奶相关的性状的遗传参数,产奶量(MY),乳脂百分比(MFP),牛奶脂肪产量(MFY),牛奶蛋白百分比(MPP),和基于随机回归测试日模型的乳蛋白产量(MPY)。对长江下游9,834头牛的95,375个测试日记录进行了估算。此外,对这些性状进行了全基因组关联研究(GWAS),基于调整后的表型。遗传性,以及标准误差,我的,MFP,MFY,MPP,泌乳期间的MPY范围分别为0.22±0.02至0.31±0.04、0.06±0.02至0.15±0.03、0.09±0.02至0.28±0.04、0.07±0.01至0.16±0.03和0.14±0.02至0.27±0.03,随着时间间隔的增加,泌乳内不同牛奶天数(DIM)之间的遗传相关性降低。两个,六,四,六,检测到三个单核苷酸多态性(SNPs),这解释了5.44,12.39,8.89,10.65和7.09%的表型变异,MFP,MFY,MPP,MPY,分别。通过分析最近的基因和检测到的SNP的200kb内的基因,富集了10个京都基因百科全书和25个基因本体论术语。此外,富集结果中可能对牛奶产量和质量起作用的17个基因被选为候选基因,包括CAMK2G,WNT3A,WNT9A,PLCB4,SMAD9,PLA2G4A,ARF1,OPLAH,MGST1、CLIP1、DGAT1、PRMT6、VPS28、HSF1、MAF1、TMEM98和F7。我们希望这项研究将为深入了解牛奶产量和品质性状的遗传结构提供有用的信息,以及有助于长江下游奶牛的基因组选择工作。
Accurately estimating the genetic parameters and revealing more genetic variants underlying milk production and quality are conducive to the genetic improvement of dairy cows. In this
study, we estimate the genetic parameters of five milk-related traits of cows-namely, milk yield (MY), milk fat percentage (MFP), milk fat yield (MFY), milk protein percentage (MPP), and milk protein yield (MPY)-based on a random regression test-day model. A total of 95,375 test-day records of 9,834 cows in the lower reaches of the Yangtze River were used for the estimation. In addition, genome-wide association studies (GWASs) for these traits were conducted, based on adjusted phenotypes. The heritability, as well as the standard errors, of MY, MFP, MFY, MPP, and MPY during lactation ranged from 0.22 ± 0.02 to 0.31 ± 0.04, 0.06 ± 0.02 to 0.15 ± 0.03, 0.09 ± 0.02 to 0.28 ± 0.04, 0.07 ± 0.01 to 0.16 ± 0.03, and 0.14 ± 0.02 to 0.27 ± 0.03, respectively, and the genetic correlations between different days in milk (DIM) within lactations decreased as the time interval increased. Two, six, four, six, and three single nucleotide polymorphisms (SNPs) were detected, which explained 5.44, 12.39, 8.89, 10.65, and 7.09% of the phenotypic variation in MY, MFP, MFY, MPP, and MPY, respectively. Ten Kyoto Encyclopedia of Genes and Genomes pathways and 25 Gene Ontology terms were enriched by analyzing the nearest genes and genes within 200 kb of the detected SNPs. Moreover, 17 genes in the enrichment results that may play roles in milk production and quality were selected as candidates, including CAMK2G, WNT3A, WNT9A, PLCB4, SMAD9, PLA2G4A, ARF1, OPLAH, MGST1, CLIP1, DGAT1, PRMT6, VPS28, HSF1, MAF1, TMEM98, and F7. We hope that this
study will provide useful information for in-depth understanding of the genetic architecture of milk production and quality traits, as well as contribute to the genomic selection work of dairy cows in the lower reaches of the Yangtze River.